In fact, the automation control technique of lighting system is over 50 years, but the building automatic still isn’t very popular use in Hong Kong. There are many lighting systems used in offices are not dimmable, so this project aim is developing a lighting system, it can adjust the indoor illumination automatically, so that, it can achieve the goal of energy efficiency. This project can divide into two parts, it has a sensor system use as the detector, and it can sense the light intensity of the environment and then automatically adjust the dimming level of electronic ballast that power the fluorescent lamps. In case, I will use the MCU to control the whole system, and it will use assemble language to program it. This report will describes the development of this control system, it will show the process and problem that meet in the project. Finally, it will display and conclude the result of this project.